The advent of MEMS technology has opened the door to the creation of power systems at unprecedented small scales. Using silicon microfabrication processes, it has been suggested that common power generation systems could be miniaturized yielding high-power density, low-cost, batch manufactured power sources. Such power sources could provide alternatives to today's batteries, with potentially higher energy densities since they could extract energy from hydrocarbon fuels. These compact and efficient power systems are becoming increasingly important for a wide range of applications, such as powering of portable electronics as well as many other applications. Typically, such applications optimally require power sources that are characterized by high power and energy density, yet have minimal size and weight, and must be cost effective.
Since the mid-1990's, development efforts have been initiated to create MEMS-based heat engines, such as gas turbine engines, internal combustion engines (rotary Wankel or piston), and thermal-expansion-actuated piezoelectric power generators. These microengines convert thermal energy (from combustion of a fuel or another heat source), sequentially into fluid, mechanical, then electrical energy. In addition, various static approaches to directly convert heat into electricity are in development for small-scale applications, including thermoelectric, thermionic, and thermophotovoltaic components coupled with a heat source. The engineering challenges to develop such multifaceted and integrated Microsystems are significant. However, most achievements to date have been for subsystems and typically at low performance levels. Thus, there remains a need to develop small and viable portable power generation systems that are capable of achieving acceptable performance power outputs and efficiencies.
Accordingly, it is desirable to provide systems and methods that overcome these and other deficiencies of the prior art.